Operation of a communication system provides for the communication of data between two or more spaced-apart locations. Communication stations positioned at the separate locations are connected by way of a communication channel upon which the data is communicated therebetween. A communication system, at which the data is sourced, forms a sending station that operates to send the data upon the communication channel. And, a communication station, positioned at the second location forms a receiving station operable to detect, and operate upon, the data communicated upon the communication channel by the sending station.
A radio communication system is a type of communication system in which the communication channel interconnecting the communication stations is formed upon a radio link. Because a radio link is utilized upon which to define the communication channels used to communicate data between the communication stations, a wireline connection is not required to be formed between the communication stations.
Communications by way of a radio communication system are therefore advantageous when the use of a wireline connection would be inconvenient or impractical. Radio communication systems are also generally more economical to install as the infrastructure costs associated with a radio communication system are generally less than the corresponding infrastructure costs of a wireline communication system.
A cellular communication system is exemplary of a radio communication system. A cellular communication system provides for the effectuation of telephonic communications by way of radio channels. Cellular communication systems have been installed throughout significant parts of the populated portions of the world. Various cellular communication standards have been promulgated, setting forth the operational parameters of different types of cellular communication systems.
Typically, a cellular communication system includes a fixed network infrastructure that is installed throughout the geographical area that is to be encompassed by the communication system. The fixed network infrastructure includes fixed-site, base transceiver stations. The fixed-site base transceiver stations are positioned at space-apart locations, and each base transceiver station defines an area, referred to as a cell, from which the cellular communication system derives its name. And, the fixed network infrastructure is coupled to a core network, such as a packet data backbone, or a public-switched telephonic network. Communication devices, such as computer servers, telephonic stations, etc., are connected to, or form portions of, the core network.
Mobile stations are utilized through which to communicate with the base transceiver stations. Mobile stations are formed of radio transceivers, usually of dimensions that permit their carriage by users. Use of the cellular communication system is permitted, typically, pursuant to a service subscription. And, users referred to as subscribers, communicate by way of the cellular communication system through utilization of the mobile stations.
Cellular communication systems are used extensively to communicate telephonically. Communication of voice, and other, data is popularly effectuated by way of cellular communication systems. Usage levels of many cellular communication systems have, at times, approached maximum system capacity. System capacity is sometimes constrained by the bandwidth allocated to the communication system. When communication capacity is met, additional communications in the communication system are not permitted until ongoing communication sessions are terminated. For CDMA system, additional communications may permitted. However, the received signal for all the mobile calls will have a low voice/data qualities. As new types of communication services are being made available for effectuation by way of cellular communication systems, capacity problems are likely to continue.
Efforts, therefore, are made to find manners by which to increase the communication capacity of cellular communication systems. Many manners by which to increase the communication capacity of the communication system also cause an increase in co-channel interference. Cell sectorization is exemplary of a manner sometimes used by which to attempt to increase communication capacity in a cellular system. Through use of a cell sectorization technique, system capacity can be increased without a corresponding increase in a co-channel interference ratio. But, use of a cell sectorization technique decreases trunking efficiency and increases handoff loading due to increased numbers of handoffs.
Cell-splitting techniques are also sometimes used to increase communication capacity in a cellular communication system. Channel capacity is increased by reducing the size of the cell. But, cell-splitting techniques also increase the handoff loading, thereby burdening the system link/switch capacity at the MSC (mobile switching center) thereof.
Because of the increased loading, as well as other difficulties, use of cell sectorization or cell splitting techniques by which to increase system capacity is somewhat limited.
Transmitter beam forming techniques are also sometimes used to increase the co-channel interference ratio (CCIR). But, beam forming typically requires the use of sophisticated, phase-array antennas and also the use of direction-of-arrival (DOA) algorithms. And, interference cancellation and multi-user detection techniques are also sometimes utilized. But, these techniques require complex computations to be carried out to perform the functions of such techniques.
Existing techniques by which to increase the communication capacity of a cellular communication system, therefore, suffer from various disadvantages due to, e.g., variously increased handoff loading or increased computational complexity, an improved manner by which to increase the capacity of a cellular communication system would therefore be advantageous.
It is in light of this background information related to communications in a cellular, or other, radio communication system that the significant improvements of the present invention have evolved.